Message::isViewed

public function isViewed(): bool
{
	if (isset($this->isViewed))
	{
		return $this->isViewed;
	}

	if ($this->authorId === $this->getContext()->getUserId())
	{
		$this->isViewed = true;

		return $this->isViewed;
	}

	$messageIds = [$this->getMessageId()];
	$this->isViewed = (new ReadService())->getViewStatusesByMessageIds($messageIds)[$this->getMessageId()];

	return $this->isViewed;
}